The present invention generally relates to removable and replaceable lids for containers, such as metal canisters for bakery goods, snacks, candy, nuts, toys, health and beauty items, apparel, coffee, tea, powdered drinks mixes, etc.
Typically, canister lids (such as removable and replaceable lids for metal containers or canisters) have been made from a single piece of metal (blank) that is formed in a press, with the skirt (side wall) of the lid being drawn and stretched, as well as being bent to 90 degrees to the top surface of the lid. While this type of construction is acceptable for many types and sizes of lids, it is not always desirable for lids having a relatively long skirt. When it is desired for the skirt of the lid to be relatively long, for example on the order of 1 or 2 inches, the drawing process limits the ability to include any ornamentation on the lid skirt. If a long-skirted lid is provided with printing on the surface prior to drawing, whether as a solid color, or actual text, the stretching of the metal that occurs in the drawing process causes the color of the ink to change. This change is due to a thinning of the ink as the metal stretches. If too much stretching occurs, then the ink simply falls off of the metal. Furthermore, printing on the lid after it has been drawn into shape is impractical due to the difficulty in printing on the surface of a three-dimensional object as opposed to printing on a flat blank. Thus, long skirted lids have not been able to have printing on them, and other decorative flourishes are required to be put onto the lid after it is formed. Therefore, a need exists for a long skirted lid construction that permits printing on the lid skirt.
As an alternative to drawing lids from a single piece of metal, some lids have been made from crimping two pieces of metal together with one piece typically forming the top of the lid and the other typically forming the lid skirt. Examples of two-piece lid constructions of the prior art are shown and described in U.S. Pat. Nos. 458,361, 811,728, 1,180,059, 1,204,093, 1,318,999, 1,446,458, 1,791,417, 2,455,767, 3,469,507, 3,543,996, the disclosures of which are incorporated herein by reference in their entireties.
Most two-piece lid constructions of the prior art include either a non-flat/non-flush top surface or a non-flat/non-flush sidewall surface, or both, which are often undesirable for several reasons, one example being the aesthetic appearance of the container. The non-flush surface is the result of a crimp connection or lock joint formed to connect the two pieces together. For example, the lid construction disclosed in U.S. Pat. No. 1,791,417, illustrated herein in FIG. 1, includes top piece 110 and side/skirt piece 120. Top piece 110 includes a generally flat central portion, 112, and a perimeter lip, 114. Skirt piece 120 includes a generally flat wall portion, 122, and a top lip, 124, extending outward from the top edge of wall portion 122 and curling downward to form a channel, 126, between the outer surface of wall portion 122 and the inner surface of lip 124. Perimeter lip 114 curls around the outer surface of top lip 124 by extending upward from the outer edge of central portion 112 over the top of top lip 124 and then downward over the outer surface of top lip 124. The outer edge of perimeter lip 114 then extends upward into channel 126. When crimped together, perimeter lip 114 and top lip 124 form a protrusion that extends both up from top piece 110 and outward from side piece 120. A somewhat similar construction is disclosed in U.S. Pat. Nos. 3,469,507 and 3,543,996 and illustrated herein in FIG. 2. As is shown in FIG. 2, skirt piece 220 includes a generally flat wall portion, 222, and a top lip, 224, extending outward from the top edge of wall portion 222 and curling downward to form a channel, 226, between the outer surface of wall portion 222 and the inner surface of lip 224. Top piece 210 includes central portion 212 and perimeter flange 214 extending upward from central portion 212 into channel 222. When crimped together, perimeter flange 214 and top lip 224 form a protrusion that extends both up from top piece 210 and inward from side piece 220. A slightly different lid construction to those described above with respect to FIGS. 1 and 2 is disclosed in U.S. Pat. No. 1,204,093 and illustrated herein in FIG. 3. As is shown in FIG. 3, top piece 310 includes a generally flat central portion, 312, and a perimeter lip, 314, extending downward from the outer edge of central portion 312 and curling inward to form channel 316 between the bottom surface of central portion 312 and the inner surface of lip 314. Skirt piece 320 includes a generally flat wall portion, 322, and a top flange, 324 extending outward from wall portion 322 into channel 316. When crimped together, perimeter lip 314 and top flange 324 form a protrusion that extends outward from sidepiece 320, leaving top piece 310 substantially flat.
The two-piece lid construction disclosed in U.S. Pat. No. 458,361 and illustrated in FIG. 4 provides for a generally flush and flat upper surface, 410 and a generally flush and flat side surface, 420. As is shown in FIG. 4, top piece 410 includes a generally flat central portion, 412, and a perimeter lip, 414, extending downward from the outer edge of central portion 412 and curling inward to form channel 416 between the bottom surface of central portion 412 and the inner surface of lip 414. Skirt piece 420 includes a generally flat wall portion, 422, and a top lip, 424, extending inward from the top edge of wall portion 422 and curling upward and outward to form channel 426. As is discussed in greater detail in U.S. Pat. No. 458,361, channels 416 and 426 are formed simultaneously by bending together the outer perimeter of top piece 410 with the outer edge, 425, of top lip 424. This initially results in the outer perimeter of top piece 410 being non-flush with side piece 420. As is discussed in U.S. Pat. No. 458,361, top piece 410 may then be made flush with side piece 420 by bending side piece 420 downward, forming bend 428. Although this results in a flush and flat upper and outside surface for the lid, the bending process is relatively complex and still results in the bottom surface of the lid having an obtrusive bulge spaced away from the inner surface of side piece 420. A need exists for a lid construction that provides a generally flush transition between the top and skirt portions of the lid, and that also provides an unobtrusive joint between the top and skirt portions of the lid.